Thermostatic cut-out switch



May 19, 1925. l 1,538,212 l R. ,W. RANDALL THERMOSTATIC CUT-OUT SWITCH j. Filed Sept 50, 1920 MW Af Patented May 19, 1925.

UNITED STATES PATENT OFFICE.

RAYMOND W. RANDALL, OF TOLEDO, OHIO, ASSIGNOB T' KOHLEB. COMPANY, OI'

' KHLER, WISCONSIN, A CORPORATION 0F WISCONSIN.

THERMOBTATIC CUT-OUT SWITCH.

Application Med September 30, 1920. Serial l0. 413,782.

To all whom it may concern.:

Be it known that I, RAYMOND W. RAN- DALL, a citizen of the United States, and resident of Toledo, county of Lucas, and State of Ohio, have invented new and useful Improvements in Thermostatic Cut-Out Switches, of which the following isl a description, reference bein had to the accompanying drawings, whic are a part of this specification.

This invention relates to thermostatic i switches and particularly to switches of this .gas en type designed for the protection of automatic gasoline engine operated power and lighting plants in the event of the closing of the motor starting circuit and a failure of the motor to start the engine within a reasonable time.

In power and :lighting plants of this type depending on a -circuit established by the closing of a lamp socket switch or the local switch for any current consuming device, a failure of the starting motor to start the e in operation to supply the demand or current may cause the motory battery to become depleted if the cause for the failure is not attended to promptly. The present invention provides a cut-out switch to open the motor circuit a short time after it is established if in the meantime it has not been effective for startingethe gas engine in operation so as to have other automatic means.

With the above and other objects in view the invention consists in a thermostatic cutout switch as herein claimed and all equivalmif th d mi? errin to e accompanyingv ra in which like characters of reference in 1- cate the same parts in different views: l

Fig. 1 is a side view of a thermostatic cut-out switch constructed in accordance with this invention and` showing in diagram possible connections for -its use in an automatic lighting and power plant;

Fig. 2 is an end view thereof;

Fig. 3 is a perspective view of the members constitutm the thermostat elements, said members being separated, and,

Fig. 4 is a perspective view of the drop frame.

In these drawings indicates an insulating base to which a bracket 11 is bolted or otherwise rigidly secured. The bracket prefn opened byl erably consists of a piece of stra metal bent `to stand out from the base an having a reduced end 12 bent downwardly, as shown. A drop frame 13, also preferabl consistmg of a piece of bent stra meta 1s fulcrumed to the downwardly lient reduced end 12 of the bracket 11 by having arms 14 cut from its downwardly bent front portion before bending same and allowed to remain horizontal in prolongation of its upper horizontal ortion so that said arms 14 embrace the ownwardly'bent reduced end 12 with a fulcrum pin 15 passed therethrough and through the end 12. The drop frame is thus pivotally mounted on the bracket and is capable of a swinging movement, being guided by a guidepin 16 riveted to the bracket 11 and passing through an opening in the4 upper horizontal portion of the dro frame.

On the ront downwardly extending end of the drop frame 13 issecured a button 17, preferably of insulating material, and preferably mounted on the same screw stud with 'it is a latch plate 18 bent so that itsend extends forwardly and upwardly through an opening cut in the drop frame. The other end of the drop frame is reduced and bent forwardly with a laterally extending arm 19 secured thereto, said arm preferably con sisting of a tube of insulating material slotted to receive the drop frame and riveted thereto.

A pair of contact su ports 2D and 20', secured to the base 10 by olts forming binding posts 21, have riveted to them spring contacts 22 which are normally in engagement with each other. One of the contact supports 20 is long enough to be lengaged by the arm 19 and thereby consitutes a stop for 'the movement of the drop frame in one direction. The other, 20', however, permits the arm to engige the lower contact 22 v'so as to separate t e contacts when the drop frame swings in the other direction agalnst the end 12 of the bracket.

t A thermostat element 23 which consists of a bifurcated strip of bimetallic thermostat'material, with its two ends secured to the base 10 by-bolts forming bindinlgadposts 24, is bent out from the base and its uoed end is bent downwardly to form a hook 25 lfor en aging' the edge of the latch plate 18 for ho dlng the drop frame in its ralsed position, shown in full lines. This thermostat element is adapted to have an electric current pass through it and offers a resistance thereto such that it is caused to be heated thereby. The material of which the thermostat element is made is arranged so that the characteristic warping incident to such heating will lift its hooked end 25, and in order to increase this action an additional heating element 26, consisting of a coil of resistance wire wound about a sheet of insulation, is attached to the under side of the thermostat element by means of metal clips 27, sheets of the insulation, such as mica, being interposed between the metal parts to prevent short circuit. This heating element 26 may be connected directly across the starting motor battery so as to be controlled by the starting motor switch and thereby receive current at the. same time as the thermostat element 23.

The diagram in Fig. 1 represents a possible circuit arrangement in which the thermostatic switch of this invention may be used. A heavy line motor circuit includes a battery 28, a starting motor 29 for the gas engine which drives the generator .of

^ a lighting system or the like, not shown, the

thermostat element 23 and a motor starting switch 30. The auxiliary heating element circuit includes the battery 28, said heating element 26 and the switch 3 0. The control circuit includes battery 28, a switch 31, which may be a hand switch or an automatic switch, an automatic switch 32, which is preferably a lgovernor controlled switch or other switch o erated to open the vcontrol circuit when t e gas engine is properly functioning, the switch contacts 22 and the solenoid 33 of the motor starting switch 30.

In operation, the closing of the control circuit by means of switch 31 energizes the solenoid 33 to close the motor starting switch 30. This completes the motor starting circuit to operate the motor 29 to start the vgas engine and generator in operation, and upon the successful accomplishment of that function the switch 32 opens the control circuit by the action of the governor or other suitable automatic means. Should the switch 32 not be opened within a reasonable time, which would indicate the failure of the gas engine to properly assume its duty of driving the generator to supply the lighting system, for some reason, the heating of the thermostat element 23 Aby the motor starting currentv passing through it or by the hea-tine coil 26 beneath it will cause it to rise to t e dotted line positior and so release the latch plate 18, permitting the drop frame to swing on the fulcrum 15 to the dotted line position thereupon opening contacts 22 by the engagement of the insulating arm 19 with the lower contact 22, and sov opening the control circuit. The

solenoid 33 will thereupon be de-energizedl` permitting the motor starting switch to drop and open the motor starting circuit.

The failure of the generator to supply the demand for service will constitute a signal giving notice that the generator plant should be inspected to remedy the cause for the failure, whether it be a lack of fuel or lubricant, failure of ignition, failure of the storage battery, or other cause. When the cause for failure has been remedied and in the meantime the cooling of the thermostat element has permitted it to resume its normal position, the button 17 may be depressed so as to again lift the drop frame and cause the latch plate to engage the hook of the thermostat element and the arm 19 to release the contact 22 to permit it to engage the-other and close the control circuit. If the service switch has remained closed during this time, this resetting operation by normal, and consequently the automatic switch 32 will be opened by the governor or other automatic means as the result of the operation of the generating plant and the motor starting switch will be opened and the thermostat element and heating coil cut out of circuit before they vhave had a chance to release the drop frame.

In practice the automatic cut-out switch of this invention is enclosed in a casing 50 and only the button 17 thereof is exposed through an opening, as shown.

What I claim as new and' desire to secure by Letters Patent is:

1. In a thermal cut-out switch, abase, a. bracket thereon having a downwardly extending end, a drop frame pivoted to said end of the bracket and engaglng it as a stop, a pin on the bracket passing through the frame to guide it in its movements, an arm` on the frame, a switch contact engaged by the arm, and a thermal element mounted on the base and engaging the drop frame for holding it in an elevated position.

2. In a thermal cut-out switch for disconnecting the battery from the starting motor of anautornatic gas engine driven generator system, comprising a pivotally mounted drop frame, a thermal element engaging the drop frame to hold it in an elevated position, a. reset button on the drop frame, and a casing through which the button is projected when the drop frame falls.

3. In a thermal cut-out switch, a base, a bracket thereon having a downwardly extending end, a drop frame pivoted to said end of the bracket and engaging it as a stop,

a switch engaged by the drop frame, a resetting button on the drop frame for returning it to its elevated positlon and a thermal element mounted on the base and engaging the drop frame for holding it in an elevated position.

4. In a cut-out switch, a base, a bracket thereon, a dro frame fulcrumed on the bracket, a switc operated by the swinging movements of the frame, a thermal element mounted on the base and engaging the frame v for holding it in its elevated position, and

a casing having an opening through which the frame may be reset to its elevated position.

5. In a thermal cut-out switch, a base, a drop frame pivotally supported on the base, a strip of bi-metalllc thermal metal secured to the base and engaging the drop frame to hold it in its elevated position, said strip havin current passing therethrough and heate thereby to cause its deflection to release the drop frame, and a switch operated by the fall of the drop frame for interrupting said current.

6. A thermal cut-out switch comprising a base, a drop frame pivotally mounted thereon, a thermal element conslsting of a bifurcated strip of bi-metallic thermal metal secured to the base and engaging the dro frame to hold it in its raised position, sai thermal element having current passing therethrough lto heat it and cause its deflection to release the drop frame, and a switch operated by the fall of the drop frame for interrupting said current. A

7. A thermal cut-out Switch comprising a base, a drop frame pivotally mounted thereon, a thermal element consisting, of a bifurcated stri of bi-metallic thermal metal secured to e base and bent to form a hook at its end for engaging the dro frame to hold it in its raised position, sai Strip'of metal having current passin therethrough to heat it and cause its deflectlon to release the drop frame, and a Switch operated b vthe. fall of operated by the fall of the drop frame for interrupting said current. v x

In testimony whereof, I aix my signature, in presence of two witnesses. RAYMOND W. RANDALL., Witnesses: Y

C. W. GWEN, MARGARET Hoovnn. 

